Indawo yethu ezindaweni

Thola phezulu ngemini ecacile futhi yonke i-star ongayibona ngamehlo akho ayilungu le-galaxie eyodwa, i-Milky Way. Uhlala ebhola letshe elijikelezayo, lijikeleza inkanyezi eyodwa ejwayelekile phakathi kwamabilione. Le ndatshana ithola ukuthi kulapho.

Yonke inkanyezi ongayibona ngamehlo akho itholakala ku-Milky Way.

Bona

Iya ngaphandle uma busuku bucacile. Ilanga elingaphansi kwenyawo lakho liyingxenye yebhola elinobubanzi be-12,742 km. Le bhola, i-Earth, lijikeleza kabili ngosuku futhi lihamba ngayinye ngenye yezinkanyezi, i-Sun, kabili ngonyaka.

Ilanga likhulu kakhulu ukuthi cishe amamilione angama-1.3 eplanethi azofaka ngaphakathi kwayo. Inzima kakhulu ukuthi igcina cishe yonke isisindo sanoma yini ejikeleza kuyo: amaplanethi, amasonto, amaplanethi ancane, ama-asteroids nama-comets. Ngokuqoka, ilanga kanye nanoma yini egcinwe yisimo sayo somhlaba siyi indlela yokukhanya.

Kusithombe esiphezulu, inkinobho emnyama phakathi yilanga. Chofoza Dlala bese ubheka amaplanethi ehamba. Uma iplanethi ingaphansi kwelanga, iyahamba ngokushesha:

• Mercury ithatha amasonto angu-88.
• Iplanethi ithatha unyaka owodwa.
• Neptune, iplanethi ehamba phambili, ithatha cishe iminyaka engu-165.

Isimo sezulu siyingxenye yezigidigidi zezinhlelo zezinkanyezi ezitholakala esigabeni esibanzi sezinkanyezi esibizwa nge- Indlela ye-Milky Way. Ngebusuku obumnyama kakhulu ungabona ukuthi iyibhande elikhanyayo elingabonakali ngaphesheya kwezulu. Yonke inkanyezi ongayibona ngamehlo akho ikhona kulo.

Ukuqonda

Amabanga endawo akhulu kakhulu ukuthi amakhilomitha azoba nzima, ngakho-ke abacwaningi belanga basebenzisa izilawuli ezinkulu.

Iyunithi ye-astronomic (au) ilingana nokuphakama okuphakathi kweplanethi nelanga. Kusuka ngo-2012 inenani elifanele: 149,597,870,700 metres, cishe amakhilomitha ayizigidi ezingama-149.6. Ngayo, i-solar system izoba lula ukuyibona:

Izwe	Ubukhulu bomhlaba
i-Mercury	0.39 noma
Iplanethi	1.00 noma
i-Jupiter	5.2 noma
i-Neptune	30.1 noma

Isikhathi sokukhanya yisikhathi esidingekayo sokukhanya ukugcwalisa umgama. Ukukhanya kuhamba nge-299,792 km ngomzuzu, ngakho:

isikhathi = ubude ÷ isivinini sokukhanya

I-1 au: 149,597,871 km ÷ 299,792 km/s ≈ 499 s, noma imizuzu engu-8 imizuzwana engu-19. Uma ubheka ilanga (kungaba njalo, kuthinta amehlo akho), uzobona ukukhanya okushiya amaminithi ayisithupha edlule. Ukukhanya kwelanga kuthatha amahora amane ukufinyelela ku-Neptune.

Iminyaka yelanga yisikhathi eside ilanga lihamba ngalo ngonyaka: cishe amakhilomitha ayi-9.46 trillion, noma ama-au angama-63,241. I-Proxima Centauri, ilanga elincane kakhulu elingamakhilomitha ayizigidi ezingama-4.2 ukusuka emhlabeni. I-Milky Way iphakathi kuka-100,000 nonyaka wokukhanya.

Umphathi

I-au yasetshenziswa ukuba * ilinganiselwe *: yacaciswa nge-Gaussian gravitational constant, ngakho ubude bayo ngamamitha kwakuyinani labo abacwaningi be-astronomiya abakwazi ukulimisela. Radar ranging of Venus and spacecraft tracking in the late twentieth century pinned it down to a few metres. Ngo-2012 i-International Astronomical Union yayenza ibe yinombolo eqinile (Isinqumo B2), ngakho-ke i-au manje iyiyunithi, njengemitha.

Okuthi siyilinganisele ngokucacile namuhla yi-sun’s gravitational parameter, GM☉ = 1.32712440041 × 10²⁰ m³ s⁻², kusuka ekuphathweni kwezinkanyezi nezindiza zesikhala. Imikhiqizo G × M ibizwa kahle kakhulu kune G noma M kuphela, ngoba G iyinye yezinto ezihlala njalo ezincane kakhulu eziziwa ephysics. Lokhu kusho ukuthi i-orbital mechanics isebenza nge μ = GM, njengoba uzobona kundlela ye-Navigator.

Izinkomba ezimbili ezisebenzayo:

1. Umhlaba awunaphakade. I-orbit yeplanethi ine-excentricity engaphezu kuka-0.0167, ngakho-ke ubude bayo kusuka kulanga busuka kumakhilomitha ayizigidi ezingama-147.1 (kuqala kukaJanuwari, i-perihelion) kuya kumakhilomitha ayizigidi ezingama-152.1 (kuqala kukaJulayi, i-aphelion). Izimo zezulu zingabangela lokhu: uJanuwari yisikhathi sobusika enyakatho ye-hemispheric. Isizathu esisemthethweni sibhalwe encwadini yesikhathi.
2. Isikhathi sokukhanya siyisinqumo esisemthethweni sezobuchwepheshe. Umlayezo we-radiyo ku-rover eMars uthatha phakathi kwamaminithi angu-3 no-22 indlela eyodwa, ngokuya ngokuthi iplanethi ngayinye ikhonaphi emijikelezweni yayo. Izindiza ezihamba phambili kufanele zikwazi ukusebenza ngazo.